Dryer system with improved throughput

ABSTRACT

A centrifugal dryer that has improved throughput capacity resulting from the combination of a high angle agglomerate catcher with optional overflow, increased dewatering capacity, a cylindrical dewatering feed chute, a modified rotor design with positionally and structurally modified lifters in the feed and dewatering section, the drying and propagating section, as well as the pellet discharge section, and an efficient circumferential foraminous membrane.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 13/533,636, filed 26 Jun. 2012, which is acontinuation application of U.S. patent application Ser. No. 12/552,163,filed 1 Sep. 2009, which claims priority to U.S. Provisional ApplicationNo. 61/093,588, filed 2 Sep. 2008, U.S. Provisional Application No.61/112,320, filed 7 Nov. 2008, and U.S. Provisional Application No.61/219,192, filed 22 Jun. 2009, the contents of which are herebyincorporated by reference as if fully set forth herein.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates generally to a dryer system, and a methodof drying, that has improved throughput capacity over conventional dryersystems, and more particularly to a dryer system combining a high angleagglomerate catcher with optional overflow, a cylindrical dewateringfeed chute for increased dewatering capacity, and a centrifugal dryerwith a modified rotor design with positionally and structurally modifiedlifters and an efficient circumferential foraminous membrane. Thepresent invention increases pellet input and output rates whilemaintaining the ability to achieve desired pellet moisture content.

2. Description of the Prior Art

The generally independent processes and equipment in the extrusion,pelletization, and drying processes of polymeric material are known.Over time, the demand for dryer systems with high drying capacities hasincreased.

Drying systems typically include both an agglomerate catcher anddewaterer that receive the slurry of water and plastic particulates inadvance of the centrifugal dryer. The agglomerate catcher catches,separates and subsequently discharges agglomerated particulates beforethe slurry enters the dewaterer. The dewaterer then separates the bulkwater from the particulates prior to entrance of the wet particulates tothe dryer. Once the bulk of the water has been removed from theparticulates, the particulates still include surface moisture that isremoved by the centrifugal dryer during elevational and centrifugalmovement of the particulates by rotation of the rotor within the dryerand circulation of air by a blower.

An agglomerate catcher is disclosed in U.S. Pat. No. 2,133,974, whereinblades are attached only at the uppermost or inlet end of a casing at asmall angle relative to the direction of the inflowing liquid. Theblades are arranged lengthwise with the direction of flow and are curvedupwardly into the flow in their distal portions. The angle between theedges of the blades and the axis of flow at the distal end isconsiderably greater than that at the proximal or inlet end. The lowerends of the blades are not secured, and the distance between the bladesdepends somewhat on the nature of the material and the size and natureof the solid objects. The length of the blades is disclosed as beingsufficient to extend completely through the flow. A rounded and smoothbaffle can be placed between these blades and the angularly inclinedscreen that is designed to receive and drain the residue that may slidedown. The screen can be pivotally mounted on the casing to allowvariation in the angle of inclination as needed.

U.S. Pat. No. 4,447,325 discloses a dewaterer including a verticaldewatering section attached to an angled feed chute screen. The verticaldewatering section includes stationary X-shaped baffle plates thatdeflect the incoming pellet water slurry, such that the pelletsintercept a screen member and are deflected, whereas the water passesthrough and is removed or recycled. The bulk dewatered pellets then passdownwardly out of the vertical dewatering section onto an angled feedchute comprising a screen member for additional dewatering andultimately to pass the significantly dewatered pellet mass into the baseportion of a dryer. Dewatering feed chute screens are also disclosed inU.S. Pat. Nos. 3,458,045; 4,476,019; and 4,896,435.

An agglomerate catcher and dewaterer is disclosed in U.S. Pat. No.6,063,296, wherein the pellet slurry is introduced vertically into theagglomerate catcher including a downwardly angled grid of elongate barsor rods spaced a distance apart smaller than the agglomerate dimensions.The rods preferentially are disclosed with saw teeth along their base tofurther deflect water from the agglomerates. A secondary agglomeratecatcher is connected to the principal dewaterer to further dewater theagglomerates prior to removal from the system. From the agglomeratecatcher, the pellet slurry enters a cylindrical dewatering area where itis deflected by a cylindrical assembly to which is attached downwardlypointing conical deflectors periodically along its vertical height. Thedeflectors redirect the pellet slurry to a screen member from which thepellets are deflected and through which the water passes. Attached tothe screen and below the downwardly pointing conical deflectors areattached inverted downwardly pointing conical annular rings. Theseredirect the pellets back toward the centrally located cylinder foradditional impact dewatering and subsequent redirection toward thescreen as above. The dewatered pellets pass through the base of thedewatering section into a dryer.

Centrifugal pellet dryers conventionally include a vertically disposedouter housing, a cylindrical screen oriented in the housing and a drivenbladed rotor positioned centrally in the screen. The rotor moves waterladen pellets or other particulates upwardly within the screen withupward and tangential velocity imparted to the particles by impact withthe blades, causing the particles to move upward and tangentiallyoutwardly into engagement with the screen for discharge from the upperend of the screen and housing, and water is discharged from the lowerend of the housing.

Dryer equipment has been introduced and used in applications followingextrusion and pelletization for many years by the assignee asdemonstrated in, for example, U.S. Pat. Nos. 3,458,045; 4,218,323;4,447,325; 4,565,015; 4,896,435; 5,265,347; 5,638,606; 6,138,375;6,237,244; 6,739,457; 6,807,748; 7,024,794; 7,171,762; 7,421,802; USPatent Application Publication Nos. 20060130353, 20080289208,20090062427, 20090110833; World Patent Application Publication Nos.WO2006/069022, WO2008/113560, WO2008/147514, and WO2009/059020; GermanPatents and Applications including DE 19 53 741, DE 28 19 443, DE 43 30078, DE 93 20 744, DE 197 08 988; and European Patents including EP 1033 545, EP 1 602 888, EP 1 647 788, EP 1 650 516, EP 1 830 963. Thesepatents and applications are all owned by the assignee and are includedherein by way of reference in their entirety.

A cascade dryer using conical screen devices is disclosed in U.S. Pat.No. 3,199,215. The water pellet slurry enters the uppermost portion ofthe drier and bulk dewatering is accomplished in the uppermost chamber.The dewatered pellets pass through a conical screen into a sequence ofconical screening devices such that the uppermost screen radiatesdownwardly from its apex and is of slightly smaller diameter than thesubsequent and upwardly turned conical screen that is attached to anenclosure. The upwardly turned screen has a through opening in itscenter to the next sequence of conical screens. To facilitate drying,heated air is introduced near the base of the cascade dryer and movesupwardly through the multiplicity of conical devices.

U.S. Pat. No. 3,477,098 discloses a centrifuge type dryer wherein thepellet slurry is introduced into the center region of a rapidly rotatingconical screen. U.S. Pat. No. 5,265,347 introduces the pellet slurryinternal to the rotor but adjacent to the inner screen and lifterportion rather than into the central region. U.S. Pat. Nos. 5,611,150;5,987,769; 6,505,416; and 6,938,357 disclose introduction of the pelletslurry through the center of the rotor, whereas U.S. Pat. Nos.3,458,045; 4,476,019; 4,565,015; 4,896,435; 5,638,606; 6,438,866; and USPatent Application Publication No. 20080072447 disclose the use of sidefeeding of the pellet slurry or the dewatered pellet mass into the baseof the dryer external to the rotor. U.S. Pat. No. 4,476,019 furtherdiscloses a centrifugal dryer in which the rotor and screen assembly canbe pivoted out of the housing for ease of access.

Tangential pellet outlets have been known to be highly effective inavoidance of build-up within the centrifugal dryers and as such havebeen disclosed exemplarily in U.S. Pat. Nos. 3,458,045 and 4,896,435.

Various rotor designs have also been disclosed including solid rotorswherein the cylindrical or tubular shell is essentially a single entityand segmented rotors wherein plates are attached to supports, thecomposite of which forms the rotor. Solid rotors are disclosed in U.S.Pat. No. 4,565,015 wherein it is described that a cylindrical hollowconstruction is supported by a web or strut elements. It is furtherdisclosed that a rotor of welded construction or of square tubing has areduced diameter, eliminates balancing issues, and is more rigid thanrotors of a bolted construction. U.S. Pat. No. 5,987,769 similarlydiscloses an elongate tubular rotor pipe suspended within the interiorof a screen member. U.S. Pat. Nos. 3,458,045; 4,218,323; 5,265,347; and5,638,606 disclose use of various supportive structural elements orspiders to which are attached backplates essentially comprising therotor.

In order for the rotor to effectively lift the pellets away from theremaining fluid up, through, and out of the dryer, various designs ofblades have been disclosed. U.S. Pat. No. 4,565,015 disclosesessentially rectangular-shaped angled lifting blades vertically alongthe length of the rotor as well as radial blades on the uppermostportion of the rotor designed to redirect the pellets from the rotor outthe pellet outlet chute and away from the drying apparatus. U.S. Pat.No. 5,987,769 discloses the use of blades that are illustrated asessentially rectangular shaped affixed to the rotor in an angularconfiguration. Between these blades are linear blades parallel to andalong the length of the rotor axis—described as kickers. Scraper blades,disclosed as being L-shaped are attached to the uppermost portion of therotor to deflect pellets out and away from the dryer. The scraper bladesare disclosed in alignment with the angular blades as well as the linearor kicker blades. U.S. Pat. No. 6,438,866 similarly discloses a lineardeflector blade in combination with the lifter blades with the lineardeflector blade illustrated angularly oriented back from the attachmentpoints as viewed in the direction of rotation of the rotor.

The lifter blades disclosed in U.S. Pat. No. 3,675,697 include twocomponents one of which is essentially planar and perpendicular to thelongitudinal or vertical axis of the rotor, and a second essentiallytriangular component attached to the planar component and pointedupwardly and angularly toward the planar component of blades in the nexthigher row. U.S. Pat. No. 6,505,416 essentially identifies four regionsof lifter blades along the vertical height of the rotor. The initial orlowermost section of blades essentially form an auger style portionallowing sufficient open area for the pellet slurry introduced betweenthese blades as it is delivered from the center of the rotor. The secondmore heavily populated portion of the rotor is in the dewatering sectionto provide additional impacts to insure that the pellets can be removedfrom the incoming fluid of the slurry and transported up and through thedrying, or third, portion where the number of blades is significantlyreduced. The uppermost or fourth portion has blades oriented parallel tothe vertical axis of the rotor to deflect the significantly driedpellets out of and away from the dryer. The blades other than those inthe fourth section are preferably involute in structure allowing forcurvature of the outer blade edge upwardly and towards the rotor todeflect the pellets toward the underside of the next row of blades andreduce the impacts directly onto the screen as these are deemeddetrimental to the quality of the pellets.

The housings of conventional dryers have been round, square, andhexagonal as disclosed in U.S. Pat. Nos. 5,987,769; 4,476,019; and5,265,347 respectively. Similarly, many and various types of screenshave been utilized, from hinged screens as disclosed in U.S. Pat. No.5,265,347, to multilayer screens as disclosed in US Patent ApplicationPublication No. 20060130353. Deflectors or flow disrupters have alsobeen disclosed for use on the screens such that banding of pellets aboutthe screen can be avoided. These disclosures include U.S. Pat. No.6,438,866 wherein angled attachments as well as angled blocks areincorporated at the juncture of the screen components. Deflector barsare attached directly to non-screen portions of the screen components asdisclosed in U.S. Pat. No. 6,739,457. US Patent Application PublicationNo. 20080289208 further discloses that the deflectors can be embossedinto non-screen portions of the screen components. Various portions ofthe dryer can be treated with abrasion-resistant non-stick surfacetreatments as disclosed in World Patent Application Publication No.WO2009/059020.

Surprisingly, with all these variants and attempts at dryer systems, areliable consistent throughput dryer remains elusive, particularly onethat has high throughput and low moisture content without compromisingfacile cleaning, manually or automatically, of an agglomerate catcherand without over-powering the dewatering components of the dryer.Furthermore, little mention of the possible impact of lifter positioningand orientation has been discussed.

BRIEF SUMMARY OF THE INVENTION

Briefly described, in preferred form, the present invention is a dryersystem, and a method of drying, with improved throughput comprising anagglomerate catcher, dewaterer (sometimes referred to herein as a “fluidremoval section”, a “solid-liquid separator” and/or a “fluid reductionsection”) and centrifugal dryer. It is understood that the term “dryersystem” or “dryer” can include various “sections”, wherein as usedherein at times, the present invention comprises distinct elements of acatcher, dewaterer and dryer, as opposed to describing the invention asa dryer having a catcher section, a dewatering section, and a dryersection. It will be understood to those of skill in the art that thereis no intended distinction when describing the present invention as adryer system comprising distinct elements, or a dryer comprising varioussections.

In a preferred embodiment of the present invention, a system forremoving surface moisture from particulate is provided, the systemcomprising a plurality of lifting blades for moving the particulatethrough system, the particulate generally drying as it is moved throughthe system, a lifting blade having a trailing edge, a leading edge, anattached edge and an outside edge; wherein at least a portion of thelifting blades in proximity to a particulate feed to the system form atleast one helical configuration; and wherein at least a portion of thelifting blades have a blade angle of less than 45° defined by theinclination of the trailing edge of a blade above that of a plane drawnhorizontally through the leading edge of a blade.

At least a portion of the lifting blades may have a tilt angle of from−20° to +40° defined as the angle of a blade from the outside edge tothat of a plane drawn through the attached edge.

In another preferred embodiment, a dryer system for removing surfacemoisture from particulate is provided, comprising a dryer comprising arotor, the rotor comprising a plurality of lifting blades for liftingparticulate through the system, the particulate generally drying as itis lifted through the system; wherein at least a portion of the liftingblades form at least one helical configuration.

The dryer system may comprise a centrifugal dryer.

The rotor may comprise at least two sections, a wet particulate feedsection into which particulate enters the system, and a drying sectionlocated above the wet particulate feed section, wherein the number oflifting blades per a given length of the wet particulate feed section isless than the number of lifting blades per the same length of the dryingsection.

At least a portion of the lifting blades of the wet particulate feedsection may form at least two helical configurations and have a bladeangle of less than 45° defined by the inclination of the trailing edgeof a blade above that of a plane drawn horizontally through the leadingedge of a blade.

At least a portion of the lifting blades of the wet particulate feedsection may form at least two helical configurations and have a bladeangle of less than 45° defined by the inclination of the trailing edgeof a blade above that of a plane drawn horizontally through the leadingedge of a blade; and wherein at least a portion of the lifting blades ofthe wet particulate feed section are longer than at least a portion ofthe blades of the drying section.

At least a portion of the lifting blades may be removably attached tothe rotor.

At least a portion of the lifting blades may have a tilt angle of from−20° to +40° defined as the angle of a blade from the outside edge tothat of a plane drawn through the attached edge.

Alternative embodiments provide a dryer system for removing surfacemoisture from particulate, the dryer system comprising a centrifugaldryer having a particulate lifting cylindrical rotor assembly positionedwithin a foraminous membrane, the cylindrical rotor assembly comprisinga cylindrical rotor assembly having a plurality of lifting blades forlifting the particulate through sections of the centrifugal dryer, theparticulate generally drying as it is lifted through each section;wherein the cylindrical rotor assembly of the centrifugal dryercomprises at least two sections, a wet particulate feed section intowhich the particulate enters the centrifugal dryer, and a drying sectionlocated above the wet particulate feed section, wherein the number oflifting blades per a given length of the wet particulate feed section isless than the number of lifting blades per the same length of the dryingsection.

At least a portion of the lifting blades of the wet particulate feedsection may form at least one helical configuration.

At least a portion of the lifting blades of the wet particulate feedsection may form at least two helical configurations, and have a bladeangle of less than 45°.

At least a portion of the lifting blades of the wet particulate feedsection may form at least two helical configurations, have a blade angleof less than 45°, and are longer than the blades of the drying section.

At least a portion of the lifting blades may be removably attached tothe cylindrical rotor assembly.

At least a portion of the lifting blades may have a tilt angle of from−20° to +40° defined as the angle of a blade from the outside edge tothat of a plane drawn through the attached edge.

To facilitate deflection of particulate off the foraminous membrane,embossed raised profiles may be provided into non-perforate areas of theforaminous membrane such that a raised area is introduced on an innersurface of that foraminous membrane.

To facilitate deflection of particulate off the foraminous membrane,deflector bars may be attached to non-perforate portions of theforaminous membrane.

To facilitate deflection of particulate off the foraminous membrane, anassemblage of releasably attached angled deflector components may beattached to non-perforate portions of the foraminous membrane. Theassemblage may be attached via a bolt and nut connection.

To facilitate deflection of particulate off the foraminous membrane, anangled deflector component may be weldingly attached to a terminus of afirst foraminous membrane and may be removably attached boltingly to acomplementarily angled deflector component attached to another terminusof a second foraminous membrane such that the two termini may beboltingly connected with the angle portions pointing symmetrically intoan inner area of the first and second foraminous membranes.

The rotor may have a bottom and a top, wherein the rotor is drivinglyconnected to a motor located in proximity of the bottom of the rotor.

The rotor may have a bottom and a top, wherein the rotor is drivinglyconnected to a motor located in proximity of the top of the rotor.

Other exemplary embodiments, a dryer system for removing surfacemoisture from particulate in the form of a slurry of particulate andfluid is provided, the dryer system comprising: a dewaterer having atleast one deflection device within a foraminous membrane, and adewatered particulate discharge chute, the dewaterer removing bulk fluidfrom the slurry of particulate and fluid; and a dryer for dryingmoisture from the particulate; wherein the dewatered particulatedischarge chute of the dewaterer comprises a cylindrical foraminousdewatered particulate discharge chute.

The angle of inclination between the foraminous membrane and thedischarge chute may be less than 90°.

The at least one deflection device of the dewaterer may comprise adownwardly and outwardly tapering frustoconical device.

The downwardly and outwardly tapering frustoconical device of thedeflection device of the dewaterer may include a spirally tapering fin.

The foraminous membrane of the dewaterer may comprise a frustoconicalforaminous membrane.

The dryer may be a centrifugal dryer and comprises a cylindrical rotorassembly, the cylindrical rotor assembly comprising at least twosections, a wet particulate feed section into which the particulate fromthe dewatered particulate discharge chute enters the centrifugal dryer,and a drying section located above the wet particulate feed section;wherein lifting the dewatered particulate through sections of thecentrifugal dryer comprises using lifting blades; and wherein the numberof lifting blades per a given length of the wet particulate feed sectionis less than the number of lifting blades per the same length of thedrying section.

The dryer system may further comprise an agglomerate catcher having anagglomerate removal grid, the agglomerate catcher removing particulateagglomerates from the slurry of particulates and fluid.

The agglomerate removal grid may have an angle of inclination of greaterthan 50°.

The agglomerate catcher may have an overflow opening through whichcollected agglomerated particulate can enter the agglomerate overflowhousing, the overflow opening having open and closure means comprising agate.

The dryer system may further comprise a pelletizer, the pelletizerforming particulate in the form of pellets.

Other exemplary embodiments provide a system for removing surfacemoisture from particulate in the form of a slurry of particulate andfluid, the system comprising an agglomerate catcher for catchingparticulate agglomerates from the slurry of particulate and fluid; aplurality of lifting blades for moving the particulate through system,the particulate generally drying as it is moved through the system, alifting blade having a trailing edge, a leading edge, an attached edgeand an outside edge; wherein at least a portion of the lifting blades inproximity to a particulate feed to the system form at least one helicalconfiguration; and wherein at least a portion of the lifting blades havea blade angle of less than 45° defined by the inclination of thetrailing edge of a blade above that of a plane drawn horizontallythrough the leading edge of a blade.

The agglomerate catcher may comprise an agglomerate removal grid thatpermits passage therethrough of the slurry of particulate and fluid, butcollects agglomerated particulate of a size greater than the gridpermits.

The system may further comprise a dewaterer having at least onedeflection device within a foraminous membrane, and a dewateredparticulate discharge chute, the dewaterer removing bulk fluid from theslurry of particulate and fluid; and a centrifugal dryer having aparticulate lifting rotor positioned within a screen, the rotorcomprising a plurality of lifting blades, for lifting the particulatethrough sections of the centrifugal dryer, the particulate generallydrying as it is lifted through each section; wherein the rotor of thecentrifugal dryer comprises at least two sections, a wet particulatefeed section into which the particulate from the dewatered particulatedischarge chute enters the centrifugal dryer, and a drying sectionlocated above the wet particulate feed section, wherein the number oflifting blades per a given length of the wet particulate feed section isless than the number of lifting blades per the same length of the dryingsection.

At least a portion of the lifting blades may have a tilt angle of from−20° to +40° defined as the angle of a blade from the outside edge tothat of a plane drawn through the attached edge.

These and other objects, features, and advantages of the presentinvention will become more apparent upon reading the followingspecification in conjunction with the accompanying drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a illustrates a dryer assembly including an agglomerate catcheroriented toward the pellet outlet chute, a dewatering section, a feedsection and a blower conduit attached to the dryer section assembly.

FIG. 1b illustrates a dryer assembly including an agglomerate catcheroriented toward and partially obscuring the blower conduit, a pelletoutlet chute, a dewatering section, and a feed section attached to thedryer section assembly.

FIG. 2 illustrates a side view of an agglomerate catcher assemblythrough the housing to show the position of the high angle agglomerategrid and the gate in the open position.

FIG. 3 is an angled perspective illustration of an agglomerate catcherassembly through the housing to show the position of the high angleagglomerate grid and the gate in the open position.

FIG. 4 is an expanded view of the angle perspective illustration of theagglomerate catcher assembly in FIG. 3.

FIG. 4a is a cross-sectional illustration of the gasket material for useon the gate in the agglomerate catcher assembly.

FIG. 4b is an expanded illustration of the flexible flap attached to theair-flow equilibration opening on the housing of the agglomerate catcherassembly.

FIG. 5a is a cross-sectional illustration of the agglomerate catchergrid.

FIG. 5b is an expanded view illustration of the support assembly for theagglomerate catcher grid.

FIG. 5c is an expanded view cross-sectional illustration of a portion ofthe agglomerate catcher grid.

FIG. 6 is a top view illustration of the agglomerate catcher assemblyshowing the agglomerate catcher grid and the plate and handles for usein its removal and insertion.

FIG. 7 is an illustration of an alternative agglomerate catcher assemblyconfiguration with an overflow attachment.

FIG. 8 is an illustration of an alternative agglomerated catcherassembly configuration showing a low angle manually operatedconfiguration.

FIG. 9 is an angled perspective illustration of an alternativeconfiguration for the agglomerate catcher grid.

FIG. 10 is an expanded view of the angled perspective illustration ofthe alternative configuration agglomerate catcher grid in FIG. 9.

FIG. 11 is an expanded view angled perspective illustration of anotheralternative configuration for an agglomerate catcher grid support.

FIG. 12 is an expanded view angled perspective illustration of a removalagglomerated catcher grid support.

FIG. 13 is an illustration of a prior art dewatering section and feedchute section.

FIG. 14 is a side view illustration of the prior art dewatering sectionand feed chute section in FIG. 13.

FIG. 15a is a cross-sectional illustration of an angled deflector in afrustoconical dewatering section.

FIG. 15b is a cross-sectional illustration of a frustoconical deflectorin a frustoconical dewatering section.

FIG. 15c is a cross-section illustration of a frustoconical deflectorwith a spirally angular fin in a frustoconical dewatering section.

FIG. 16 is an illustration of a dryer assembly section to which isattached a dewatering section and a cylindrical feed chute section.

FIG. 17 is a cross-sectional illustration of the dryer assembly sectionin FIG. 16 illustrating the juncture between the cylindrical feed chutesection and its intersection with the housing of the dryer assemblysection.

FIG. 18 is a cross-sectional illustration of the dryer assembly sectionin FIG. 16 in opposite orientation showing the rotor assembly.

FIG. 19 is a cross-sectional illustration of a prior art rotor showingsupport structures and backplate assemblies.

FIG. 20a is a cross-sectional illustration of a prior art rotor supportstructure from FIG. 19.

FIG. 20b is a cross-sectional illustration of an alternative prior artrotor support structure from FIG. 19.

FIG. 21 is a cross-sectional illustration of the rotor assembly fromFIG. 18.

FIG. 21a is an expanded view cross-sectional illustration of the topportion of the rotor assembly in FIG. 21.

FIG. 21b is an expanded view cross-sectional illustration of the bottomportion of the rotor assembly in FIG. 21.

FIG. 22 is an illustration of the rotor assembly from FIG. 18.

FIG. 23 is an illustration of an alternative rotor assembly from FIG.18.

FIG. 24a is an illustration of the blade design on the rotor in FIG. 18.

FIG. 24b is an illustration of an alternative blade design on the rotorin FIG. 18.

FIG. 24c is an illustration of another alternative blade design on therotor in FIG. 18.

FIG. 25 is an illustration of a multi-layer screen.

FIG. 26 is an expanded illustration of the multi-layer screen in FIG.25.

FIG. 27a is an illustration of a sintered foraminous membrane in whichhorizontal elements are connected perpendicularly in relation to thevertical elements.

FIG. 27b is a cross-sectional illustration of the foraminous membrane inFIG. 27a wherein the horizontal elements are attached in a verticallyperpendicular orientation to the vertical elements.

FIG. 27c is a cross-section illustration of the foraminous membrane inFIG. 27a wherein the horizontal elements are attached angularly to thevertical elements.

FIG. 27d is an illustration of a sintered foraminous membrane in whichthe horizontal elements are attached angularly to the vertical elements.

FIG. 27e is an illustration of a sintered foraminous membrane in whichthe horizontal elements are attached angularly to the vertical elementsin an orientation opposite to that of FIG. 27 d.

FIG. 28a is an illustration of an embossed deflector near the terminusof a foraminous membrane.

FIG. 28b is an illustration of an embossed deflector in a non-perforateand non-terminal portion of a foraminous membrane.

FIG. 29 is a cross-sectional illustration of an embossed deflector on aportion of a cylindrical foraminous membrane.

FIG. 30a is an illustration of a removable deflector attached to aforaminous membrane.

FIG. 30b is a cross-sectional illustration of the removable deflectorattached to a foraminous membrane in FIG. 30 a.

FIG. 31 is a cross-sectional illustration of components of deflectorassemblies attached to foraminous membrane for connection of thoseforaminous membranes.

FIG. 32 is an expanded view of the deflector assemblies in FIG. 31.

DETAILED DESCRIPTION OF THE INVENTION

Although preferred embodiments of the invention are explained in detail,it is to be understood that other embodiments are contemplated.Accordingly, it is not intended that the invention is limited in itsscope to the details of construction and arrangement of components setforth in the following description or illustrated in the drawings. Theinvention is capable of other embodiments and of being practiced orcarried out in various ways. Also, in describing the preferredembodiments, specific terminology will be resorted to for the sake ofclarity.

It must also be noted that, as used in the specification and theappended claims, the singular forms “a,” “an” and “the” include pluralreferents unless the context clearly dictates otherwise. For example,reference to a pellet or lifter is intended also to include theprocessing of a plurality of pellets or lifters. References to acomposition or fluid containing “an” ingredient or “a” constituent isintended to include other ingredients or other constituents,respectively, in addition to the one named.

Also, in describing the preferred embodiments, terminology will beresorted to for the sake of clarity. It is intended that each termcontemplates its broadest meaning as understood by those skilled in theart and includes all technical equivalents which operate in a similarmanner to accomplish a similar purpose. As just a few examples, theterms “pellet”, “water”, “pellet slurry”, “foraminous membrane”, and“rod” are discussed below.

For example, the term “pellet” can include, and be interchangeable with,micropellets or particulates. Such pellets/micropellets/particulates canbe of many shapes, and is typified by regular or irregular shapeddiscrete particles without limitation on their dimensions, includingflake, stars, spheres, conventional pellets, chopped fibers, and othershapes. They also can be round, square, rectangular, triangular,pentagonal, hexagonal or otherwise geometric in cross-section,star-shaped or other decorative designs, and can be the same ordifferent when viewed in a second cross-section perpendicularly to thefirst. Preferably, the pellets are spherical to lenticular for the majoror preponderant rotational component.

For example, the term “water” includes not only water itself, but alsowater with one or more additives included, which are added to the water.

For example, the term “pellet slurry” includespellets/micropellets/particulates in a fluid, which can include a water(with one or more additives included) or other transportation fluidswith one or more additives included useful for drying systems of thepresent invention.

For example, the term “foraminous membrane” includes a material havingapertures distributed therein. Materials used in the formation of theforaminous membrane will be understood by those of skill of the art tobe selected to provide the desired physical properties such as weight,rigidity and the like, and are also selected to provide the desiredchemical properties. The apertures can vary in number and placement, andcan include various shapes, including round, oval, square, rectangular,triangular, polygonal, and others. The “foraminous membrane” can includea grid, perforated plate or screen that permits passage of pelletstherethrough, wherein at least some fluid exits through the foraminousmembrane, with perhaps small fines or other small-sized materialescapable through the apertures.

For example, the terms “bar”, “rod” or similar terms can include formsof many geometries, including round, square, and rectangular, and can behollow or solid.

Ranges may be expressed herein as from “about” or “approximately” oneparticular value and/or to “about” or “approximately” another particularvalue. When such a range is expressed, another embodiment includes fromthe one particular value and/or to the other particular value.

By “comprising” or “containing” or “including” is meant that at leastthe named compound, element, particle, or method step is present in thecomposition or article or method, but does not exclude the presence ofother compounds, materials, particles, method steps, even if the othersuch compounds, material, particles, method steps have the same functionas what is named.

It is also to be understood that the mention of one or more method stepsdoes not preclude the presence of additional method steps or interveningmethod steps between those steps expressly identified. Similarly, it isalso to be understood that the mention of one or more components in adevice or system does not preclude the presence of additional componentsor intervening components between those components expressly identified.

Referring to the drawings, FIGS. 1a and 1b illustrate a preferredembodiment of dryer assembly 10 comprising an agglomerate catcher 100,dewatering unit 200 with feed chute 300, and centrifugal dryer 400. Thedryer system 10 can comprise the agglomerate catcher assembly 100attached to the fluid reduction section assembly 200 and feed chuteassembly 300 through which defluidized material is introduced to thedryer section assembly 400 to which is attached outlet chute 900 andblower duct 980. FIGS. 1a and 1b differ in illustration of alternateorientations of the agglomerate catcher assembly 100 in relation todryer section assembly 400. In FIG. 1b a portion of the agglomeratecatcher assembly 100 is in front of and partially obscures the blower980 as illustrated.

The basic sequence of the drying process as it relates to FIG. 1afollows introduction of a pellet slurry from upstream processes throughinlet 102 of agglomerate catcher assembly 100, wherein the slurry passesthrough an agglomerate removal grid 104 allowing the deagglomeratedpellet slurry to pass through and subsequently into the fluid reductionsection assembly 200, wherein the pellet-to-fluid ratio is increased,effectively concentrating the slurry. This concentrated pellet slurrycontinues into and through the feed chute assembly 300, wherein furtherfluid reduction is achieved, and the slurry then introduced into thelower portion of the dryer section assembly 400. The pellets aresignificantly reduced in fluid content as they move upwardly and out ofthe dryer section assembly 400 through outlet chute 900 and subsequenttransport, storage, and/or post-processing as necessitated by thespecific process.

In a preferred embodiment of the instant invention as illustrated inFIG. 2, the agglomerate catcher assembly 100 comprises inlet 102attachedly connected to the top of housing 106 through which the pelletslurry is introduced across the agglomerate removal grid 104. Housing106 can be many geometries, including round or square, and is preferablyrectangular in shape in the portion enclosing the agglomerate removalgrid 104, tapering inwardly and downwardly to outlet 108. Removably andpreferably hingedly attached to the top of the housing 106 isagglomerate grid removal door 110 with handle 112 through which theagglomerate removal grid 104 can be removed. Optional access door 114with handle 116 also can be removably and/or hingedly attached to thetop of housing 106. Similarly, optional viewing port 118 can be fixedlyattached to housing 106, the location of which is shown by way ofillustration but is not limited to the location shown.

Agglomerate removal grid 104 is inserted into and through agglomerategrid removal door 110 into a pair of grooved tracks 120 fixedly andangularly attached to the sides of housing 106 from the entry of theagglomerate grid removal door 110 to, but not through, the juncture 122of housing 106 and agglomerate overflow housing 124 attachably,preferably boltingly, attached thereto. The wall formed by juncture 122has an overflow opening (not shown in FIG. 2) through which theagglomerates can be removed. This overflow opening can be sealinglyclosed, manually or automatically, by gate 126 fixedly and hingedlyattached across the uppermost edge of the overflow opening. A controlcylinder 127 is attached to gate 126 and agglomerate overflow housing124. Automatic closure, hydraulically and preferably pneumatically, ofgate 126 is preferential and can be done by switch or by programmablelogic control (“PLC”). Optionally, the opening and closing of gate 126can be operated and controlled at fixed time intervals as maintained byPLC.

Agglomerate overflow housing 124 can be many geometries, includingsquare or round, and is preferably rectangular with the lower portiontapering downwardly and inwardly toward agglomerate overflow outlet 128.Access port 130 is attachedly, preferably hingedly, connected toagglomerate overflow housing 124 to facilitate ease of access to theregion of the overflow opening in juncture 122 and the lower portion ofthe agglomerate removal grid 104. Attached to and passing throughagglomerate overflow housing 124 is a pair of manual safety rods withhand cranks 132 (only one visible) that when manually rotatedthreadingly move a cylindrical rod into the housing such that when thegate 126 is open, the manual safety rods with hand cranks 132 adjust thecylindrical rod into position beneath the gate 126 to prevent accidentalor premature closure.

FIG. 3 better illustrates a preferred embodiment of the agglomeratecatcher assembly 100 three-dimensionally, wherein like numbers reflectlike components in FIG. 2. FIG. 4, similarly numbered, orients a portionof agglomerate catcher assembly 100 such that an overflow opening 134through juncture 122 is more clearly illustrated. A mounting bracket 136for control cylinder 127 attaches to vertical support 138 (onlypartially illustrated as configured) and is subsequently attached,preferably by welding, to agglomerate overflow housing 124.

Gate 126 comprises a metal plate 140 reinforced by rectangular frame 142and a multiplicity of longitudinal braces 144. The edge of the metalplate 140 is fitted circumferentially with gasket material, preferablysilicone, that is held in place by a suitable clasp. A preferred gasket150 as illustrated in cross-section in FIG. 4a has a slotted portion 152that fits securely over the metal plate 140 as well as a compressiblecylindrically hollow portion 154 that sealingly fits between the metalplate 140 and the wall formed by juncture 122. Without intending to belimited, other suitable gasket materials and gasket configurations asare known to those skilled in the art can be utilized to achievecomparable results.

Returning to FIG. 4, further illustrated is air-flow equilibrationopening 131 that optionally can be covered with flexible flap 133 (FIG.4b ), the uppermost edge 135 of which is attachedly connected to, andpreferably boltingly connected to, housing 106. Flexible flap 133 can beof many flexible materials, preferably polymeric, and more preferably ispolypropylene. The flexible flap 133 completely covers air-flowequilibration opening 131 (not shown in FIG. 4b ) and overlaps housing106 sufficiently to prevent its being drawn backwardly through theopening into the interior of the housing 106. One or more optionalweighting supports 137 can be attachedly connected horizontally acrossthe face of the flexible flap. The weighting supports 137 preferablycomprise a bar boltingly connected through the flexible flap to asecond, similar underside bar (not shown) that differs only in thelength, such that the bar on the underside does not contact housing 106,and thus is narrower than the width of the flexible flap 133 by at leastthe dimensions of the overlap of the flexible flap 133 on housing 106 atboth ends of the underside bar. The weighting supports can be made ofmany materials and preferably are the same composition as is housing106. This flexible flap 133 is capable of freely opening and closing,allowing equilibration of pressure as is dependent on the air flow drawnthroughout the entire assembly. This prevents excessive air from beingdrawn into the process uncontrollably.

As shown in FIG. 4 and detailed in FIGS. 5a, 5b, and 5c , theagglomerate removal grid 104 comprises a multiplicity of longitudinalrods 160 weldingly attached to a multiplicity of triangular supports 162that are in turn weldingly attached to horizontal rods 164 that slideinto and along grooved tracks 120. To accommodate space for thehorizontal rods 164 to slide unobstructedly along grooved tracks 120,the outermost longitudinal rods 160 are weldingly attached to anglebracket 166 that subsequently is welded to the side of the adjacenttriangular support 162. As the size of the dryer assembly increases,additional support beneath the similarly-increasing agglomerate removalgrid 104 can become important. To facilitate this strengthening, amultiplicity of support rods 170, (FIG. 4 and detailed in FIG. 5a ), arewelded to the top of housing 106 between the pair of grooved tracks 120as well as to the wall formed as juncture 122. Additionally, supportrods 168 are weldingly attached to the multiplicity of horizontal rods164. To facilitate movement of the support rods 168 along support rods170, it is preferential that they be inverted v-angle supports asillustrated in cross-section in FIG. 5a . Thus the v-portion of supportrod 168 slides without inhibition along a geometrically cooperatingv-portion of support rod 170.

To better facilitate removal of the agglomerate removal grid 104 throughagglomerate removal door 100, (FIGS. 2, 3, and 4), the uppermost edge ofthe agglomerate removal grid 104 can be attached, preferably weldingly,to the underside of the agglomerate removal door. More preferably, asillustrated in FIG. 6, a plate 172 can be weldingly attached to theupper ends of support rods 168 on agglomerate removal grid 104. To thisplate 172 are attachedly connected at least one handle 174 that can bemanually grasped or attached to an appropriate lifting device, such as acrane, for example, to be removed from the agglomerated catcher assembly100.

In another preferred embodiment of the present invention, FIG. 7illustrates an overflow agglomerate catcher assembly 1000 comprising ahousing 1002 that can be many geometric configurations, including roundor square, but preferably rectangular in shape, and tapers downwardlyand inwardly to outlet 1004. Hingedly attached to the front of housing1002 is access door 1006 with handle 1008. The door can be hinged at theside or at the top as space and ease of access allows. The pellet slurryenters through inlet 1010 as described above and passes over agglomerateremoval grid 1012. Attached, preferably by bolting, to the back ofhousing 1002 and covering an overflow opening, not shown, is overflowhousing 1014. The overflow opening can optionally be covered by aforaminous membrane device as described in detail hereinbelow. Theforaminous membrane device can be removably attached at the juncture1016 between the housing 1002 and the overflow housing 1014 as bybolting or insertion into a slotted groove for ease of removal to clean.Alternatively, the screening device can be fixedly attached, as bywelding, to the juncture 1016. This embodiment is preferable formaterials prone to high levels of agglomeration formation, particularlysticky or tacky materials, such that build-up of agglomerates can betolerated, wherein the flow of the pellet slurry is not obstructed bythe build-up. The choice of the screening device is of particularimportance to minimize clogging during an overflow situation. Thisembodiment is further preferable for low fluid temperature processingand manual operations where risk of burn or injury to the operator isminimal.

FIG. 8 illustrates another preferred embodiment, providing a relativelysimple manual and low-temperature embodiment of an agglomerate catcherassembly 1100, wherein there is no overflow housing and the agglomerateremoval grid 1112 is at a considerably lower angle of inclination thanof other disclosed embodiments. As illustrated, the manual agglomeratecatcher assembly 1100 comprises a housing 1102 that can be manygeometries, including round or square, but is preferably rectangulartapering downwardly and inwardly toward outlet 1104. Hingedly attachedto the front of housing 1102 is access door 1106 with handle 1108 thatcan be hinged from the side or the top as space and configuration allow.As before, the pellet slurry is introduced through inlet 1110 and passesacross agglomerate removal grid 1112 at a lower angle of inclination.

The agglomerate removal grids 104 (FIG. 2), 1012 (FIG. 7), and 1112(FIG. 8) can be at many angles of inclination 1116 ranging from 0degrees to greater than 50 degrees as measured from a horizontal planethat transects the lowest point of the agglomerate removal grid asindicated by the dotted line 1114 in FIG. 8. Preferably the angle ofinclination 1116 ranges from approximately 20 degrees to greater than 50degrees, more preferably from approximately 40 degrees to greater than50 degrees and most preferably greater than 50 degrees. The lower angleof inclination (for example, 0 degrees to 20 degrees for grid 1112 ofFIG. 8) is particularly useful for manual low fluid temperatureprocesses to allow ease of removal from accumulating agglomerates. Asthe process moves from manual to automatic operation, the angle ofinclination is favorably raised to minimize the need for operatoractivity. Thus, in high volume processes and/or high temperatureprocesses, an angle of inclination greater than 50 degrees is mostpreferable to allow the accumulation of agglomerates to purge itselfupon opening of the gate 126, as exemplified in FIG. 2, without need ofassistance from an operator. The subsequent release of the agglomeratesinto the agglomerate overflow housing 124 and through the outlet 128allows remote collection and/or transport of the accumulatedagglomerates away from the area of operation. Subsequently, outlet 128can be connected to a waste bin, a recycle bin, or other storage andtransport mechanisms known to those skilled in the art. \

Alternative agglomerate catcher assemblies are contemplated. FIG. 7illustrates an agglomerate removal grid 1012 that has flat area at itslowest portion formed by welding horizontal rod component 1020 tovertical rod components 1022. This allows for accumulation of a largerquantity of agglomerates as can be common in sticky and tackyformulations. FIGS. 9 and 10 illustrate an alternative agglomerateremoval grid 1212 design wherein the lowermost ends of the longitudinalrods 1214 are bent or preferably welded in a downwardly turned angle toform vertical component 1216. The longitudinal rods 1214 can beweldingly attached to a multiplicity of support rods 1218 (FIGS. 9 and10) or to a triangular bracket 1222 (FIG. 11) that are similarly weldedto horizontal rods 1220 (FIGS. 9, 10, and 11). The agglomerate removalgrid 1212 can be fixedly attached to the housing (shown as transparentfor illustration purposes) by welding, and preferably are removablyattached by threadingly inserting bolts 1224 into the complementarilythreaded ends of the multiplicity of horizontal rods 1220 (FIGS. 9, 10,and 11). FIG. 12 illustrates a simple attachment method wherein anL-angle 1230 is welded onto the wall of the housing (shown astransparent for illustration purposes) near the juncture of two walls ofthat housing 1232, for example. Into this L-angle is placed thehorizontal rod 1220 to which is weldingly attached a multiplicity oflongitudinal rods 1214 to form an agglomerate removal grid that manuallycan be inserted or removed from the agglomerate catcher assembly. FIG.12 is illustrative of an assembly useful in small volume, low fluidtemperature operations or where large quantities of agglomerates are notanticipated.

FIG. 11 further illustrates an alternative configuration for the gasketin which a rectangular gasket 1226 provides insulation between panel1234 and angled panel 1236 of access door 1106. Overlap gasket 1228 ispositioned between angled plate 1236 and backplate 1238 with the excessmaterial extending past the edges of both plates to form a sealing flap.The gasket material can be of many suitable materials including neopreneand silicone, and is preferably ethylene propylene diolefin monomercopolymer (“EPDM”). The assemblage is boltingly connected.

FIGS. 13 and 14 illustrate a prior art fluid reduction section assembly200 and feed chute assembly 300 to which is attached agglomerate catcherassembly 100. Within the housing 202 is at least one verticalcylindrical screen member or foraminous membrane 204 circumferentiallysurrounding perpendicular deflector blades 206 that are semi-circular ortruncated semi-circular in shape and angularly inclined and attachedlyconnected along support rod 208 with at least one collar 210 containingset screw 212 (FIG. 14). The base of the foraminous membrane 204 isfittingly positioned onto flange 214 that tapers downwardly and inwardlyand is attached to feed chute assembly 300. The feed chute assemblycomprises housing 302 to which is fixedly attached rectangularforaminous membrane 304 along its bottom length. Details of this knownassembly are disclosed in U.S. Pat. No. 4,447,325 owned by the assigneeof the present invention, and the contents of which are included hereinin their entirety by way of reference. The feed chute assembly isattachedly connected to dryer section assembly 400 through inlet 306.

The known perpendicular deflector blades 206 shown in FIGS. 13, 14, and15 a can be replaced by a downwardly and outwardly taperingfrustoconical device 220 weldingly connected to collar 222 with setscrew 224 to removably attach the entire assembly to support rod 226 asillustrated in FIG. 15b . Optionally, a spirally tapering fin 226 can beweldingly attached to frustoconical device 220 to confer additionalspiral motion to the pellet slurry to improve the fluid removalefficiency, as shown in FIG. 15c . FIGS. 15a, 15b, and 15c illustrate amore preferred embodiment of the present invention wherein thecylindrical foraminous membrane 204 of FIGS. 13 and 14 are replaced by afrustoconical foraminous membrane 230 to which is weldingly attached aplanar annular disk 232 such that the outer diameter of the planarannular disk 232 is the same as the largest or top diameter of thefrustoconical foraminous membrane 230 and the inner diameter of theplanar annular disk 232 is larger than the largest diameter of theperpendicular deflector blades 206 and/or the largest diameter or thebottom of the frustoconical device 220. This allows the support rod 226or the individual deflector units to be removed and/or replacedindependently of the foraminous membrane 204 or the frustoconicalforaminous membrane 230. Three such units are shown attachedlyconnected, preferably by welding, without intending to be limited as atleast one such assemblage and preferably at least two or more suchassemblages are utilized in the fluid reduction section assembly 200.Descriptions of the foraminous membranes are detailed hereinbelow. Thefrustoconical foraminous membrane 230 can be at angle 231 being up to 90degrees, and is preferably in the range of 20 degrees-90 degrees, andmore preferably in the range of 40 degrees-90 degrees.

Turning now to FIG. 16, a portion of dryer assembly 10 without theagglomerate catcher assembly is shown in a different orientation ascompared with FIGS. 1a and 1b . As described hereinabove, inlet 102 isattachedly connected to fluid reduction section assembly 200 and feedchute assembly 300 through which defluidized material is introduced todryer section assembly 400 to which is attached outlet chute 900. Accessdoors 240 and lower access door 320 are attached and preferably hingedlyattached to housing 202 and feed chute housing 322, if separate inconstruction, and have attached handles 242. In a preferred embodimentof the present invention, flange 214 is attachedly, preferablyboltingly, connected to adapter flange 324 that is subsequentlyattached, preferably boltingly, to cylindrical foraminous feed chute 326angled downwardly for optional attachment to the inlet of dryer sectionassembly 400 the attachment of which is not shown in this illustration.To clarify this specific attachment point, FIG. 17, in the orientationas from FIG. 1a , shows the dryer section assembly 400 through which aplane has been passed to cut away near the attachment site. Thuscylindrical foraminous feed chute 326 is weldingly attached to mountingbracket 328 and optionally attachedly, preferably boltingly, connectedto the housing 402 of dryer section assembly 400 to provide feed chuteoutlet 330. Descriptions of the cylindrical foraminous feed chute 326are detailed hereinbelow.

The housing 402 for dryer section assembly 400 in FIG. 17 can be of manygeometries, and illustrated here as rectangular for sake of simplicitywithout intending to be limited. The housing 402 can have a number ofaccess doors 404 attached thereto, preferably hingedly attached, forfacilitation of access to the foraminous membranes and rotor assembliescontained therein and to be described subsequently.

In FIG. 18, a portion of dryer assembly 10 without the agglomeratecatcher assembly is shown with a plane transecting the assembly suchthat the rotor assembly 500 and circumferential foraminous membrane 800are shown within dryer section assembly 400. As illustrated, in a morepreferred embodiment of the present invention, the inlet 102 is attachedto fluid reduction section assembly 200 and feed chute assembly 300,wherein a preferred embodiment of the present invention includes flange214 connected to adapter flange 324 that is subsequently attached tocylindrical foraminous feed chute 326 angled downwardly for attachmentto the inlet to foraminous membrane 800 at the screen inlet 802 insidehousing 402.

The angle of inclination 231 of the foraminous membrane 304 in FIG. 14and the cylindrical foraminous feed chute 326 in FIG. 18 as measuredfrom the dotted line 332 drawn perpendicularly to the housing 402 at theintersection of the respective feed chute is less than 90 degrees, andis preferably from approximately 20 degrees to approximately 70 degrees,and more preferably is from approximately 30 degrees to approximately 60degrees.

The rotor assembly 500 in FIG. 18 can be segmental, solid, andcombinations thereof. Segmental rotors as illustrated in FIGS. 19, 20 a,and 20 b comprise support assemblies 502 weldingly attached to hub 504containing at least one set screw 506 for attachment, removably andadjustably, to shaft 508 (FIG. 19). Support assemblies 502 can be ofmany designs and geometries as are known to those skilled in the art,and are shown exemplarily as decagonal in FIG. 20a and angularlydecagonal in FIG. 20b without intending to be limited. Support assembles502 can comprise struts, braces, and structural components 508 invarying numbers and angularities to planar orientation that weldinglyattach to hub 504 as well as to circumferential attachment components510 generically identified for purposes of illustration as thesestructures are known to those skilled in the art. To these supportassemblies 502 are boltingly attached backplates 512 to which areattachedly connected, boltingly and/or weldingly, angularly orientedblades 514.

A solid rotor assembly 500, FIG. 21, comprises circumferentially anduniformly geometric, preferably cylindrical, rotor 520 to which areattached, preferably by welding, angularly oriented blades 522. Anannular disk 524 is welded to the top of the rotor 520 such that theouter diameter of the disk is at least the same as the diameter of therotor 520. The inner diameter of annular disk 524 is the same as theouter diameter of upper hub component 526 to which it is weldinglyattached. A multiplicity of internal annular disks 528 are weldinglyattached to the inner circumference of the rotor 520 to provideadditional structural support such that the inner diameter issignificantly greater than the diameter of shaft 530. A tapered bushing532 is placed onto shaft 530 and inserted into upper hub component 526and is fittingly and securingly adjusted to insure simultaneous andsynchronous rotation of the rotor 520 with shaft 530 as better detailedin FIG. 21a . Rotor 520 can be assembled from a multiplicity ofcomponents, preferentially cylindrical components, that are weldinglyattached. The internal annular disks 528 optionally can be placedinternal to these welds as well as a multiplicity of other locations forpurposes of reinforcement without intending to be limiting.

In FIG. 21 and detailed in FIG. 21b , an annular disk 534 is weldinglyattached inside the rotor 520 a distance 536 at least as far from thelowermost edge as the smallest vertical dimension of the base structureabout which it rotates, as detailed hereinbelow. A tapered bushing 538is placed onto shaft 530 and inserted into lower hub component 540 andis fittingly and securingly adjusted to insure simultaneous andsynchronous rotation of the rotor 520 with shaft 530. Between taperedbushing 538 and circumferential locking collar 542 is a cylindricalspacer 544 that provides additional support to prevent possible failureof the lower rotor bushing support components. Locking collar 542 fitsinto a groove 546 circumferentially inscribed about shaft 530.

As further illustrated in FIG. 21b , optionally mounted above annulardisk 534 is annulus 548 circumferentially about rotor 530 and weldinglyattached to annular disk 534. To the annulus 548 can be weldinglyattached a multiplicity of fins 550 perpendicularly oriented to theannulus to provide additional structural support as needed. Beneathannular disk 534 can be weldingly attached optional deflector fins 552that facilitate removal of potential contaminants within the rotationalareas of the dryer section assembly 400. These fins 552 can be manygeometries in an angularity of placement and are preferentiallytriangular with torsional angularity toward the direction of rotation.The torsional angularity of fins 552 can be 90 degrees or less asdetermined relative to the perpendicular plane of the annular disk 534.Preferably the torsional angularity is approximately 20 degrees up toand including 90 degrees, and more preferably the torsional angularityis at least 40 degrees up to 90 degrees.

Returning to FIG. 18, the shaft 530 extends below solid rotor assembly500 into and through a two-part support structure 554 a and 554 b thelatter of which extends upwardly and interiorly of the rotor itself asindicated by dotted line 554 c. The distance 536 described in FIGS. 21and 21 b is defined as at least the distance equivalent to the height ofthe uppermost component 554 b and fortuitously placed positionally abovethe dotted line 554 c as illustrated in FIG. 18. It is about thistwo-parted support structure that the base of the foraminous membrane800 fits securely as detailed hereinbelow. The shaft 530 extendsdownwardly from the two-part support structure 554 a and 554 b throughbaseplate 556, bearing 558 into and through driven pulley 560. Thedriven pulley is attached by a belt 562 to a drive pulley 564 on thedrive shaft 566 of motor 570. Without intending to be limited, the motor570 can also be drivingly connected to the top of the shaft and can alsobe directly and collinearly attached directly to the shaft as isunderstood by one skilled in the art. As the dryer size increases, thecollinearly direct drive can be problematic as the torque alsoincreases; thus, the drive and driven mechanisms are preferred.Similarly increased size confers increased weight; thus, the motor 570as illustrated in FIG. 18 is a more preferred configuration.

The belt 562 can be a chain or a belt including flat belts, round belts,V-belts, rotary belts or chain belts, cog belts or timing belts, and thelike wherein cog belts are preferred for use to avoid undesirable slipor backlash between the drive and driven mechanisms. More preferably thecog belt is not prone to slip and is chemically resistant with minimumstretch or distension on regular use. Most preferably, the cog beltprovides reproducible translation of motion from the drive mechanism tothe driven mechanism at slow speeds under high torque loading withoutslip and without distension.

According to a preferred embodiment of the present invention, thepositioning and orientation of the blades 522 on and about the rotorassembly 500, and most preferably in the solid rotor configuration, areof considerable significance in determining the efficiency of theoverall drying process. As such, the rotor assembly 500 of FIG. 22 isarbitrarily sectioned into four regions for consideration. A wet pelletfeed section 602 receives the deliquified pellets from the feed chuteassembly 300 (FIG. 18) and redirects the flow of the pellets fromapproximately horizontal to more spirally vertical providing additionalvelocity on impact with the blades 522 while further facilitatingremoval of residual fluid through the same impacts with the blades 522as well as with the foraminous membrane 800. Being able to feed the wetpellets into the dryer is an important concern in consideration of thisregion of the drying process. Following the wet pellet feed section 602is a residual fluid reduction section 604, wherein the superficial orsurface liquid on the pellets is effectively removed by impacts with theblades 522 in combination with the foraminous membrane 800.

As fluid on the pellets becomes more significantly reduced from inlet,through wet pellet feed section 602, and through residual fluidreduction section 604, the drying pellets propagate into and through adrying section 606 where the final trace of moisture achievable for aparticular material is accomplished. The now dry pellet is redirectedout of the dryer as facilitated by an ejection section 608, and exitsthrough the pellet outlet chute 900 as illustrated in FIGS. 1a, 1b , 16and 17.

Drying of the pellets thusly is affected by the residence time in thedrying process, the efficiency of the drying equipment, the chemicalcomposition of the pellets, the temperature of the pellets, thetemperature maintained in the drying equipment, the air-flow through thedrying equipment, the frequency and effectiveness of the collisions ofthe pellets, the varying moisture levels occurring in different portionsof the drying equipment through which the pellets must pass, as well asthe nature and chemistry of the fluid being removed from the pellets.Importantly, the design of the rotor is of importance to how all ofthese variables can be positively modified to affect a dry pellet onexit from the drying process.

The typical conventional rotary places the blades at 45 degrees anglesrelative to a horizontal axis transcribed across the rotor. To extendthe residence time of the pellets, the angles can be lowered, thusproviding less lift and slowing down the vertical rise through thedryer.

To facilitate feeding into the dryer it was discovered that the pelletswere effectively being blocked from entry into the dryer in many caseswhere a large number of blades were present at the inlet with highrotation rates of the rotor. The angle of the blades was also discoveredto be problematic in that the impact angle of the pellets hitting theblade, if incorrectly positioned, could potentially reject the pelletback out of the drying and into the feed chute assembly. Number ofimpacts can be greatly enhanced by using more blades and positioningthem closer, and this is of particular importance as the pellet massand/or the pellet size decreases as with flake materials or smalldiameter or essentially micropellets.

It was further found that the proximity of the trailing edge of thelower tier of blades to the leading edge of the next tier of blades, ifimproperly spaced, can leave a gap through which banding about ahorizontal plane along the inner screen becomes problematic. The shapeof the blade also influences migration of the pellets through the dryingprocess. The angle at which the fluid is effectively removed from thepellets and impacts the screen to efficiently be removed from theprocess is also important. It was also realized that passing a planethrough the rotor at a 45 degrees angle also changes the orientation ofthe blade with respect to a position further up or further backpositionally along that plane; thus, movement of the blades along thatplane had varying and significant effects on the throughput rate anddrying efficiency of the process as a whole. The width of the spacebetween the blades and the wall of the screen as well as the width andorientation of the blades proximal to the outlet chute are also ofimportance.

Thus, in a preferred embodiment of the instant invention as illustratedin FIG. 22, wet pellet feed section 602 has a reduced number of bladesessentially forming at least one helical configuration, and preferablyat least two helical configurations of the blades in which the bladeangle defined by the inclination of the trailing edge above that of aplane drawn horizontally through the leading edge is no greater than 45degrees, and preferably is less than 45 degrees, most preferably lessthan 35 degrees. The helical blades 610 of wet pellet feed section 602can be longer than the blades in other portions of the assembly, andpreferably are at least 1.25 times the length, more preferably at least1.5 times the length. The angle of the blade from the outside edge tothat of a plane drawn through the attached edge can be in a range from 0degrees to +20 degrees, and preferably is from 0 degrees to minus 20degrees. The blades lowest positionally in the helix are preferably at alower angle of the trailing edge as related to a plane through theleading edge than are those progressively spiraling upward through theassembly and the angle of the lowest blade as related to the outsideedge relative to a plane through the attached edge is preferably 0degrees to less than 40 degrees, and most preferably is 0 degrees toless than 30 degrees.

As the greatest mass of material including residual fluid impacts thehelical blades 610 directly, they can be provided with at least oneangular support 612 perpendicularly attached, preferably weldingly, tothe underside of the helical blade 610 and angularly attached,preferably weldingly, to the rotor 520. The angularity with respect tothe rotor 520 is such that the angular support 612 is perpendicularlyoriented to the face of the rotor itself and is angularly disposed inits attachment to the face of the rotor such that it retains itsperpendicularity with the helical blade 610 at the angle at which theblade is inclined as considered from the trailing edge of the bladerelative to a plane drawn through the leading edge of the same blade.Preferably at least two angular supports 612 are attached, preferablyweldingly, to each helical blade 610.

Turning now to the residual fluid reduction section 604 of rotor 520shown in FIG. 22, the blade angle of the trailing edge of blade 614relative to a plane drawn through the leading edge of the same blade canbe the same as, and preferably is steeper than, that of the wet pelletfeed section 602 and can be the same as the blade angle of the dryingsection 606. Wherein fluid removal from a particular material is moreproblematic or requires additional residence time, the blade angle inthe wet pellet feed section 602 can be lowered to reduce the effectivelift and thus increase the number of collisions as well as the residencetime of the pellets in this section of the dryer.

To improve residence time and/or effective reduction of fluid,preferably the angle of the blade 614 is greater than that of the blade610 and less than that of the blade 616 in the drying section 606.Additional collisions can be achieved by placing a greater number ofblades 614 in the wet pellet feed section 602 such that the distance 618between successive rows of blades 614 is reduced. Similarly increasingthe angle of the outside edge of the blade 614 relative to that of aplane drawn through the attachment of the blade 614 to rotor 520 can beused to effectively increase the number of collisions. Preferably thisangle is from 0 degrees to at least 20 degrees. Alternatively theoutside edge and/or the trailing edge can be curved relative to the bodyof blade 614, but this is preferably avoided because of the increaseddifficulty introduced in reproducibly controlling the manufacture andassembly of increasingly complex curves in the component parts.Optionally supports can be added to the blades 614 as needed asdescribed above for helical blade 610.

As noted hereinabove, the blades 616 in the drying section 606 can be atthe same angle as that of the blades 614 in the wet pellet feed section602, wherein the angle of consideration is that of the trailing edge ofthe blade relative to a plane drawn through the leading edge of the sameblade. Preferably this angle of blade 616 is at least the same and morepreferably is greater than that of the angle of blade 614. As moreresidence time is deemed necessary, the angle can be reduced.Alternatively and optionally, the angle of the blades 616 in the lowerportions of the drying section 606 can be different than that ofprogressively higher blades in the same section to facilitate more readyacceleration of the rapidly drying pellets through and ultimately out ofthe drying process. Additionally the distance between blades, thecurvature of the outside edge of the blades, the curvature of thetrailing edge of the blades, and the curvature of the leading edge ofthe blades can be different in different portions of the drying section606 as needed. Preferably for ease of construction the number ofvariations across the drying section 606 is minimized and mostpreferably the blades, angles, and curvature are uniform across theregion.

For materials that tend to be tacky, sticky, and are prone to want toadhere, it is advantageous to reduce the blade width in an upper dryingsection 607 of drying section 606. Preferably, the blade width is atleast 5% narrower, more preferably it is at least 10% narrower, and mostpreferably is at least 20% narrower than blades 616 of the rest ofdrying section 606. Without intending to be bound by any theory, thiseffectively increases the open, non-collision area in the upper regionof the dryer thus reducing the likelihood as well as the energetics ofthe collisions between particles.

The ejection section 608 in FIG. 22 is comprised of blades 620 that areintended to redirect pellets as they move spirally up the dryer suchthat they are horizontally propagated out of the dryer in the area ofthe pellet outlet chute 900 (see FIG. 1a ). The blades 620 are at anglesat least that of the angle of blades 614 and blades 616, and preferablyare at angles greater than that of these blades. Most preferably, theangle of the uppermost edge of blade 620 relative to that of thelowermost edge of the same blade is at least 45 degrees, still morepreferably the angle is at least 70 degrees, and most preferably is atleast 80 degrees and greater. The blades 620 can be positioned about therotor 520 such that they are directly adjacent to the trailing edge ofthe preceding row of blades, and preferably are between the trailingedges of adjacent blades in the preceding row of blades as illustratedin FIG. 22. The width of the blades 620 must not exceed the distance 622between the rotor and the outermost edge of annular disk 524, andpreferably is less than that distance 622. Optionally, the blades 620can be omitted from the assembly. Blades 620 are attachedly connected,preferably weldingly, to the rotor 520 and optionally can be attached tothe annular disk 524, preferably by welding. Wherein the blade 620 isaligned with blade 616 in the preceding row, the trailing edge of blade616 and the lowermost edge of blade 620 can optionally be weldinglyattached.

The respective sections of the rotor assembly 500 can be of manyproportionate arrangements on the rotor. Preferably, the wet pellet feedsection 602 is the same height as the uppermost height of the screeninlet 802 inside housing 402 as shown in FIG. 18, the residual fluidreduction section 604 is at least one-tenth the height of the dryingsection 606, and the ejection section 608 is the same height as that ofthe outlet 902 to outlet chute 900 (FIG. 17). When the width of theblades 616 is reduced in the upper drying section 607, the preferredheight of that section is at least one fifth that of the height of therotor 520.

The shape of the helical blades 610 as well as blades 614, 616, and 620in FIG. 22 can be of many geometries, and preferably are a modifiedquadrilateral as illustrated in FIGS. 24a, 24b , and 24 c. Attachmentedge 630 conforms to the radius of rotor 520, FIG. 22, and isillustrated here as a line for simplicity of illustration as the radiusof different size dryers will vary. Trailing edge 632 is no greater inlength than is leading edge 634 and the length of outside edge 636 isdependent on the relative lengths of trailing edge 632 and leading edge634. In FIG. 24a the trailing edge 632, leading edge 634 and outsideedge 636 are all approximately linear resulting in approximately angularintersections. In FIG. 24b corner 638 and corner 640 are radiused toreduce the angularity, and in FIG. 24c the outside edge 642 is radiusedalong its length. The various blades in the various regions can be ofsimilar design, but preferably are of different design to servedifferent purposes respective of their locations.

Returning to FIG. 22, the relative positioning of the blades can be ofmany arrangements on the rotor 520, and preferably for ease ofmanufacturing the blades in the residual fluid reduction section 604 andthe drying section 606, are in rows aligned in parallel planes that lieperpendicularly to the axis of the rotor as well as in columns inparallel lines aligned with the axis of the rotor as shown. The trailingedge of blades in one row are preferably in the closest verticalproximity to the leading edge of blades in the next higher row, and theplane drawn through the trailing edge of the blade in one row does nothave to be in the same plane drawn through the leading edge of the bladein the next higher row. Similarly, the vertical plane formed by thetrailing edges of the blades in a column do not have to be in the samevertical plane formed by the leading edges of the blades in an adjacentcolumn. The trailing edge of the uppermost helical blade 610 in the wetpellet feed section 602 preferably is in the closest proximity to theleading edge of the lowest blade in the residual fluid reduction section604, but is not necessarily coplanar therewith. In an alternativeconfiguration in FIG. 23, the blades in all equivalent sections,equivalently numbered, of rotor assembly 500 are of approximately thesame shape and size and all rows of blades are in parallel planesoriented perpendicularly to the axis of the rotor 520 and the columns ofblades are in parallel lines aligned with the axis of the rotor 520. Asdiscussed before, it is preferred that blades 610 in the wet pellet feedsection 602 have at least one support 612 as described hereinabove forthe helical blades 610, FIG. 22.

The multiplicity of foraminous membranes including the multiplicity ofcylindrical screen members or foraminous membranes 204 in FIG. 13, therectangular foraminous membrane 304 in FIG. 14, the frustoconicalforaminous membrane 230 in FIGS. 15a, 15b, and 15c , the cylindricalforaminous feed chute 326 in FIGS. 16, 17, and 18, as well as themultiplicity of circumferential foraminous membranes 800 and anymultiplicity thereof, can be of at least one layer in composition. Thesize, composition, and dimensions of the foraminous membranes shouldaccommodate the pellets being generated and can be perforated, punched,pierced, woven, or of another configuration known to those skilled inthe art and can be the same or different in construction, composition,and style. As the pellet size decreases in diameter, preferably theforaminous membranes will be composed of two or more layers that can beof similar or different composition, design, and size. Multilayerforaminous membranes are described in US Patent Application PublicationNo. 20060130353 owned by the assignee of the present invention, thecontents of which are disclosed herein by way of reference in theirentirety. FIG. 25 illustrates an exemplary three layer foraminousmembrane 804 which is subsequently detailed in FIG. 26, wherein thethree layers include an outer support layer 806, an optionalintermediate layer 808 and an inner layer 810. The foraminous membranesare fixedly attached by latches, clamps, bolts, and other mechanismsappropriately understood by those skilled in the art.

Compositionally, the foraminous membranes can be composed of moldedplastic or wire-reinforced plastic and compositionally can bepolyethylene, polypropylene, polyester, polyamide or nylon, polyvinylchloride, polyurethane, or similarly inert material that capablymaintains its structural integrity under chemical and physicalconditions anticipated in the operation of the centrifugal pelletdryers. Preferably, the foraminous membrane can comprise a perforated,punched, pierced, or slotted metal plate to form openings that can beround, oval, square, rectangular, triangular, polygonal, or otherstructures to provide open areas for separation and subsequent drying,and is of suitable thickness to maintain the structural integrity of theoverall assembly and flexible enough to be contoured, exemplarilycylindrically, to fit tightly and positionally in the appropriate fluidremoval, feed chute and drying assemblages. The metal plate ispreferably 18 gauge to 24 gauge, and most preferably is 20 to 24 gaugein thickness. The metal can compositionally be aluminum, copper, steel,stainless steel, nickel steel alloy, or similarly non-reactive materialinert to the components of the drying process. Preferably the metal isstainless steel and most preferably is Grade 304 or Grade 316 stainlesssteel and their low carbon equivalents as necessitated environmentallyby the chemical processes undergoing the drying operation.

Alternatively and more preferably, the foraminous membrane can be anassembled structure or screen composed of wires, rods, or bars, stackedspirally, angularly or orthogonally, or interwoven, and welded, brazed,resistance welded or otherwise adhered in position. The wires, rods, orbars can be plastic or wire-reinforced plastic compositionally similarto the molded plastic described above or can be metal, similarly andcompositionally delineated as above and can be geometrically round,oval, square, rectangular, triangular or wedge-shaped, polygonal andother geometric structure as is known to those skilled in the arts. Thewires, rods, or bars across the width of the foraminous membrane can bethe same as or different dimensionally as the wires, rods, or barslongitudinally or as otherwise known to those skilled in the art. FIGS.27 a, b, c, d, and e illustrate a sintered foraminous membrane 812 wherearrows 814 indicate a preferred direction of flow across the structure.In FIG. 27a the surface rods 816 are oriented perpendicularly to thesupport rods 818, whereas in FIGS. 27d and 27e the surface rods 816 areoriented angularly to the support rod 818. It is to be understood thatin a cylindrical structure, FIGS. 27d and 27e are illustrative ofdifferently handed spiral orientations of the surface rods 816. FIG. 27bshows the surface rods 816, exemplarily shown as triangles withoutintending to be limited, attachedly connected perpendicularly to thesupport rods whereas FIG. 27c illustrates the surface rods 816 attachedat an angle such that an edge of the surface rod is angularly tiltedinto the direction of flow. The angle of the surface rod 816 relative tothe support rod 818 in FIGS. 27a, d, and e is preferably 0 degrees to±30 degrees and is preferably 0 degrees to ±15 degrees. The angle ofrelief formed by the plane of the top of the surface rod 816 and aperpendicular line drawn from the upstream most edge of the surface rod816 and perpendicular to the support rod 818 is greater than 30 degreesbut less than 90 degrees, and preferably is between 45 degrees up to andincluding 90 degrees. The distance 820 between edges of the surface rodsmust be narrower than the smallest dimension of the pellets to beretained by the appropriate foraminous membrane.

To facilitate deflection of the pellets off the foraminous membrane 800in FIG. 18, it is known as disclosed in US Patent ApplicationPublication No. 20080289208, owned by the assignee of the presentinvention and included herein by way of reference in its entirety, toemboss raised profiles into non-perforate areas of a foraminous membranesuch that a raised area is introduced on the inner surface of thatforaminous membrane. This is illustrated in FIG. 28a wherein the raisedembossed area 830 is placed in a non-perforate terminus of theforaminous membrane 800 and in FIG. 28b wherein the raised embossed area830 is in a non-perforate mid-portion of the foraminous membrane 800.FIG. 29 further illustrates this for a portion of a cylindricalforaminous membrane 800 wherein the raised embossed area 830 extendsinto the open area between the foraminous membrane 800 and the rotor520. Arrow 832 indicates the direction of rotation of the rotor 520 andarrow 834 indicates the deflection of the pellets encountering theraised embossed area 830.

Alternatively, as illustrated in FIG. 30a in accordance with thedisclosures in U.S. Pat. No. 6,739,457 also owned by the assignee of thepresent invention and included herein by way of reference in itsentirety, deflector bars 850 can be attached to the non-perforateportions of a foraminous membrane 800. This is better detailed in FIG.30b wherein an assemblage of a support 852 on the non-perforate portionof foraminous membrane 800 is attached to the angled deflector component854 utilizing bolt 856 and nut 858 to form the deflector assemblage suchthat the flow about the screen is deflected away from the screen asillustrated by arrow 860. In the preferred embodiment of the presentinvention as illustrated in FIG. 31, angled deflector component 862 isweldingly attached to the terminus of a foraminous membrane 800component and is removably attached boltingly to a complementarilyangled deflector component 864 attached to another terminus of the sameor different foraminous membrane 800 such that the two termini areboltingly connected with the angle portions pointing symmetrically intothe inner area of the foraminous membrane. By virtue of the symmetry,the foraminous membranes can be joined without concern for orientationand similarly can be reversed to maximize the life of the foraminousmembrane as illustrated. Only if there is an orientational specificityof the foraminous membrane components will this become a constraint. Theassembly is illustrated three-dimensionally in FIG. 32 wherein only thelocus of the foraminous membrane attachment is illustrated by thereference number 800.

Returning summarily to FIGS. 1a and 1b , a number of fluid reductionassemblages can be used in fluid reduction section assembly 200 and canbe used in many combinations. It is also understood where reduction offluid is not preferential, the fluid reduction assemblages are removableand the foraminous membrane components can be effectively excluded byincorporation of an equivalent or comparable non-foraminous component.Similarly, a number of feed chute assemblages can be used in the feedchute assembly 300 in many combinations, and this too can effectively beblocked by incorporation of an equivalent or comparable non-foraminouscomponent. In FIG. 18, at least one circumferential foraminous membrane800 and preferably a multiplicity of circumferential foraminousmembranes can be used in the process such that a continuous cylindricalforaminous membrane is formed throughout the entire verticality of thedryer section assembly 400. The bottom-most section of the foraminousmembrane in the preferred embodiment is modified to attachingly,preferably boltingly, connected to the inlet 802 from the feed chuteassembly 300 as is described hereinbefore. Alternatively at least oneupper component of the circumferential foraminous membrane 800 can bereplaced with an equivalently circumferential non-perforate component tofacilitate processing. These non-perforate equivalents or comparablyequivalent structures are an integral consideration wherein particularlytacky or adherent materials are being processed.

Of similar consideration, abrasion-prone and problematic build-up areasthrough the entire dryer assembly 10, FIGS. 1a and 1b can be surfacetreated in accordance with disclosures in World Patent ApplicationPublication No. WO2009/059020 owned by the assignee of the presentinvention and included herein by way of reference in its entirety.Surface treatments as described herein can involve at least one or moreprocesses inclusive and exemplary of which are cleaning, degreasing,etching, primer coating, roughening, grit-blasting, sand-blasting,peening, pickling, acid-wash, base-wash, nitriding, carbonitriding,electroplating, electroless plating, flame spraying including highvelocity applications, thermal spraying, plasma spraying, sintering, dipcoating, powder coating, vacuum deposition, chemical vapor deposition,physical vapor deposition, sputtering techniques, spray coating, rollcoating, rod coating, extrusion, rotational molding, slush molding, andreactive coatings utilizing thermal, radiational, and/or photoinitiationcure techniques, nitriding, carbonitriding, phosphating, and forming oneor more layers thereon. The layers can be similar in composition,different in composition, and many combinations thereof in multiplelayer configurations.

Composition of the apparatus components are preferably metal andcompositionally can be aluminum, copper, steel, stainless steel, nickelsteel alloy, or similarly non-reactive material inert to the componentsof the drying process. Preferably, the metal is stainless steel, andmost preferably is Grade 304 or Grade 316 stainless steel and their lowcarbon equivalents as necessitated environmentally by the chemicalprocesses undergoing the drying operation.

Upstream processes can include melt and extrusional processes subjectedto underfluid pelletization, recycle washes and processing, fluidicthermal treatments, washes, rinses, and the like wherein pellets arecontained in a fluid medium to form a slurry. The fluid medium can be afluid, preferably not flammable, that can be readily evaporated and mostpreferably is water. The fluid medium can contain additives andprocessing aids as are known to those skilled in the art. The fluidmedium can also be a moderately volatile material that upon subjectionto the centrifugal process is significantly reduced in quantity, andthus becomes more practical for additional downstream processes such asrinsing, extraction, and the like.

Pellets as described herein can include flake, granule, and powder andcan be many geometries including but not limited to round, oval, square,rectangular, hexagonal, pentagonal, spherical, lenticular, and can beirregularly shaped. The pellet composition can include polymers, filledpolymers, reactive polymers, cross-linkable polymers, polymerformulations, recyclables, waxes, asphalts, adhesives, gum bases and gumbase formulations, organic solids, inorganic solids, and the likewithout intending to be limited. The pellets are not limited in size orthroughput rate and it is understood that the foraminous membranes mustbe satisfactorily of small e nough particle size to prevent undue lossto the desired particle range.

1. A dryer system for removing surface moisture from particulatecomprising: a dryer comprising a rotor assembly, the rotor assemblycomprising a plurality of lifting blades for lifting particulate throughthe system, the particulate generally drying as it is lifted through thesystem; wherein the rotor assembly comprises at least two sections, alower, wet particulate feed section into which the particulate entersthe dryer, and a drying section located above the wet particulate feedsection; and wherein the lifting blades of the lower, wet particulatefeed section have a blade angle of less than 45° defined by theinclination of the trailing edge of a blade above that of a plane drawnhorizontally through the leading edge of a blade.
 2. The dryer system ofclaim 1, wherein a lowermost lifting blade of the lifting blades has atilt angle of from 0° to +40°, and another lifting blade of the liftingblades has a tilt angle of from 0° to ±20°, the tilt angles beingdefined as the angle of a blade from the outside edge to that of a planedrawn through the attached edge.
 3. The dryer system of claim 1, whereinthe blade angle of the lifting blades of the lower, wet particulate feedsection is 35° or less defined by an angle of inclination of thetrailing edge of a blade above that of a plane drawn horizontallythrough the leading edge of a blade.
 4. The dryer system of claim 1,wherein at least a portion of the lifting blades of the lower, wetparticulate feed section form at least one helical configuration.
 5. Thedryer system of claim 1 further comprising a centrifugal dryer.
 6. Arotor assembly for use in a dryer system, the rotor assembly comprising:a first plurality of outwardly extending lifting blades that form a wetparticulate feed section, the first plurality of lifting blades beingarranged in horizontal rows and configured to upwardly directparticulate entering the dryer system; and a second plurality ofoutwardly extending lifting blades that form a drying section positionedabove the wet particulate feed section, the second plurality of liftingblades being arranged in horizontal rows and configured to upwardlydirect particulate from the wet particulate feed section, wherein thefirst plurality of lifting blades have a blade angle of less than 45°defined by the inclination of the trailing edge of a blade above that ofa plane drawn horizontally through the leading edge of a blade.
 7. Therotor assembly of claim 6, wherein the second plurality of liftingblades are arranged such that the number of lifting blades per a givenlength of the drying section is greater than the number of liftingblades per the same length of the wet particulate feed section.
 8. Therotor assembly of claim 6, wherein at least a portion of the firstplurality of lifting blades form at least one helical configurationcomprising lifting blades from at least a first and an adjacent secondhorizontal row of the first plurality of lifting blades such that atrailing edge of the lifting blades in the first horizontal row arepositioned in the closest vertical proximity, relative to the otherlifting blades, to a leading edge of the lifting blades in the secondhorizontal row.
 9. The rotor assembly of claim 8 further comprising acentrally disposed cylindrical rotor, wherein at least a portion of thelifting blades are removably attached to and outwardly extend from thecylindrical rotor.
 10. The rotor assembly of claim 8, wherein thelifting blades of the first and second horizontal rows progressivelyspiral upwardly.
 11. A rotor assembly comprising: a wet particulate feedsection having a first plurality of outwardly extending lifting bladesarranged in horizontal rows and configured to upwardly directparticulate; and a drying section positioned above the wet particulatefeed section and having a second plurality of outwardly extendinglifting blades arranged in horizontal rows and configured to upwardlydirect particulate received from the wet particulate feed section,wherein the first plurality of lifting blades have a blade angle of lessthan 35° defined by the inclination of the trailing edge of a bladeabove that of a plane drawn horizontally through the leading edge of ablade.
 12. The rotor assembly of claim 11, wherein the second pluralityof lifting blades are arranged such that the number of lifting bladesper a given length of the drying section is greater than the number oflifting blades per the same length of the wet particulate feed section.13. The rotor assembly of claim 11, wherein at least a portion of thefirst plurality of lifting blades form at least one helicalconfiguration comprising lifting blades from at least a first and anadjacent second horizontal row of the first plurality of lifting bladessuch that a trailing edge of the lifting blades in the first horizontalrow are positioned in the closest vertical proximity, relative to theother lifting blades, to a leading edge of the lifting blades in thesecond horizontal row.
 14. The rotor assembly of claim 13 furthercomprising a centrally disposed cylindrical rotor, wherein at least aportion of the lifting blades are removably attached to and outwardlyextend from the cylindrical rotor.
 15. The rotor assembly of claim 14,wherein the first and second pluralities of lifting blades are removablyattached to the cylindrical rotor.
 16. The rotor assembly of claim 13,wherein the lifting blades of the first and second horizontal rowsprogressively spiral upwardly.
 17. The rotor assembly of claim 13,wherein the first plurality of lifting blades form at least two helicalconfigurations.
 18. The rotor assembly of claim 13, wherein the firstplurality of lifting blades are longer than at least a portion of thesecond plurality of lifting blades.
 19. The rotor assembly of claim 13,wherein a lowermost lifting blade of the first and second pluralities oflifting blades has a tilt angle of from 0° to +40°, and another liftingblade of the first and second pluralities of lifting blades has a tiltangle of from 0° to ±20°, the tilt angles being defined as the angle ofa blade from the outside edge to that of a plane drawn through theattached edge.
 20. The rotor assembly of claim 11 further comprising atop and a bottom, whereon one or more of the top and the bottom isconfigured to be drivingly connectable to a motor.